Liquid bread for lunch

The reason so many monasteries brewed beer was because during Lent the monks were required to fast. They had to do something with all that grain on hand so they used it to make beer. Beer was safer to drink than water in the Middle Ages. Alcohol killed the parasites and bacteria in the water. It was also something the monks could sell to pilgrims staying at their monasteries. Monks introduced the first hops as preservatives.